The present invention generally relates to devices and methods for treating septal defects or shunts in the vascular system. More particularly, the present invention relates to devices and methods for treating septal defects within the heart of a human being.
Heart defects including abnormal openings within the heart and vascular system may occur either congenitally or by acquisition. These abnormal openings commonly occur across a septum. A septum is generally defined as a thin wall of tissue that divides two or more areas within the body, for example heart chambers.
The most common congenital heart defects include ventricular septal defects, atrial septal defects, and patent ductus arteriosus. Left-to-right ventricular septal defects and patent ductus arteriosus typical result in the left side of the heart having to work harder because some of the blood it pumps will recirculate through the lungs instead of circulating throughout the body. Atrial septal defects typically result in blood being shunted from the left atrium to the right, thus overloading the right side of the heart. These conditions have significant consequences if left untreated including hypertension, increased pulmonary arterial pressure, strain on the heart muscle, and ultimately heart failure.
For many years, septal defects were corrected by open-heart surgery where a surgeon would cut into the heart and suture the defect closed. If the defect was too large to be sutured, a patch of a biologically compatible material could be sewn onto the septum to cover the defect. A variety of methods for treating septal defects that utilize intravascular catheters have been developed as less invasive alternatives to open heart surgery. In general, these methods comprise some form of a patch that is delivered to the defect through an intravascular catheter. The patch is then secured to the defect in order to suitably repair the defect.
One of the first such devices was disclosed by King et al. in U.S. Pat. No. 3,874,388. The King device comprises a pair of mechanical umbrella-like patches that are be connected to one another. Since the disclosure of the King device, a number of septal closure devices have been disclosed and patented. These devices generally have in common the use of a single intravascular catheter that is used to secure a patch to a septal defect. The use of a single catheter can limit the utility of such devices since it may often be difficult to center and place the patch across a small hole within a constantly moving heart. A need, therefore, exists for devices and methods for treating septal defects that have an improved ability to center and place a patch across a septal defect.
The present invention comprises unique devices and methods for treating septal defects. Moreover, the present invention includes devices and methods for treating septal defects that comprise an improved ability to center and place a patch across a septal defect. The patch system may comprise a first catheter, a second catheter, and a bridge member that may be adapted to extend between the first catheter and the second catheter.
The first catheter and the second catheter may be steered to opposite sides of a septal defect. Once located on opposite sides of a septal defect, the bridge member may be extended so as to pass from a first lumen of the first catheter, through the septal defect, and into a second lumen of the second catheter.
A first patch may be urged toward the septal defect along the bridge member by a first pusher. Similarly, a second pusher may be used to move a second patch over the bridge member toward the septal defect. The first patch and the second patch may be connectable across the septal defect.
In alternative embodiments of the invention, the first patch and the second patch may be connected by differing mechanisms. For example, the first patch may comprise an outer surface having a plurality of loops, and the second patch may comprise an outer surface having a plurality of complementary hooks. The hooks may engage the loops when the first patch and the second patch are brought into contact with one another and substantially remain connected. Alternatively, the first patch and second patch may comprise an outer surface including a magnet or adhesive.
In an exemplary embodiment, the first patch and the second patch may be mechanically connectable. For example, the first patch may comprise an outer surface including a chamber and a deflectable flange. In addition, the second patch may comprise an outer surface including a shank and one or more rings defining a recess therebetween. Preferably, the chamber is adapted to receive the shank and lock in place when the deflectable flange becomes disposed within the recess. Alternatively, the first patch may comprise an outer surface including a chamber having threads, and the second patch may comprise an outer surface including a shank having threads. The second patch may further comprise a head having a slot. An alternative pusher may be used that includes a complementary head adapted to engage the slot. The chamber may be adapted to threadably receive the shank while the complementary head is engaged with the slot.